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Comparison

Ipamorelin vs Sermorelin

Ipamorelin is gHRPs & ghrelin mimetics; Sermorelin is GHRH analogs. They are compared here because they are frequently considered against each other, not because they act alike.

On published evidence alone, Sermorelin is the better documented of the two (regulator approved). That is a statement about the state of the literature, not a recommendation.

Ipamorelin Sermorelin
Class GHRPs & ghrelin mimetics GHRH analogs
Evidence Preliminary human Regulator approved
Human trials ~5 ~20
Half-life ~2 hours ~10-20 minutes
Reported range 200-300 mcg 200-500 mcg
Frequency 1-3x daily, on an empty stomach Once daily at bedtime
Routes Subcutaneous Subcutaneous
FDA approved No Yes
Research use only Yes No
Banned in sport Yes Yes
Studied for Growth hormone elevation, Recovery, Sleep quality, Body composition Growth hormone deficiency diagnosis and paediatric treatment, Age-related GH decline, Sleep quality, Body composition
Reported side effects Head rush on injection, Transient hunger, Water retention, Lethargy Injection-site erythema, Flushing, Headache, Transient dizziness

Ipamorelin

Ipamorelin is a pentapeptide agonist at the growth hormone secretagogue receptor, the same receptor targeted by endogenous ghrelin. Unlike the earlier GHRPs it produces a GH pulse without meaningful elevation of adrenocorticotropic hormone, cortisol or prolactin, which is the basis of its reputation as the cleanest compound in the class. It is short-acting and is typically dosed alongside a GHRH analog to exploit the synergy between the two receptor pathways.

Sermorelin

Sermorelin is a truncated analog of growth-hormone-releasing hormone comprising residues 1-29, the minimum sequence required for receptor activation. It binds the GHRH receptor on anterior pituitary somatotrophs and stimulates synthesis and pulsatile release of endogenous growth hormone. Because it acts upstream on the pituitary rather than replacing growth hormone directly, release remains subject to negative feedback from somatostatin and IGF-1, which is the usual argument for a lower risk of supraphysiologic exposure than exogenous hGH.

Ipamorelin vs Sermorelin: common questions

What is the difference between Ipamorelin and Sermorelin?

Ipamorelin is gHRPs & ghrelin mimetics and Sermorelin is GHRH analogs, so they act on different pathways. Ipamorelin: The most receptor-selective of the growth-hormone-releasing peptides, notable for leaving cortisol and prolactin essentially unchanged. Sermorelin: The first 29 amino acids of endogenous growth-hormone-releasing hormone, and the shortest fragment that retains full biological activity.

Which has stronger evidence, Ipamorelin or Sermorelin?

Sermorelin has the stronger evidence base (regulator approved, about 20 human studies) compared with Ipamorelin (preliminary human).

Are Ipamorelin and Sermorelin FDA approved?

Only Sermorelin is FDA approved (Diagnostic assessment of pituitary GH secretory capacity (Geref); Treatment of idiopathic growth hormone deficiency in children with growth failure (Geref, approved 1997; discontinued by the manufacturer in 2008, not for safety reasons)). Ipamorelin is not approved for any indication.

References

Regulatory and primary sources

  1. PubChem compound record (CID 9831659) ↗ · structure, identifiers, synonyms
  2. WADA Prohibited List ↗ · current year
  3. FDA: Unapproved drugs and "research use only" products ↗ · regulatory status of non-approved products
  4. CAS Registry Number 170851-70-4 ↗ · chemical identity
  5. PubChem compound record (CID 16132413) ↗ · structure, identifiers, synonyms
  6. DailyMed: FDA-approved labeling for Sermorelin ↗ · indications, dosing, warnings as approved
  7. FDA Drugs@FDA database ↗ · approval history
  8. CAS Registry Number 86168-78-7 ↗ · chemical identity

Published literature

  1. Mayfield CK, Bolia IK, Feingold CL, et al.. Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians.Am J Sports Med 2026.PubMed 41476424 · doi:10.1177/03635465251357593
  2. Rahman OF, Lee SJ, Seeds WA. Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions.J Am Acad Orthop Surg Glob Res Rev 2026.PubMed 41490200 · doi:10.5435/JAAOSGlobal-D-25-00236
  3. Mendias CL, Awan TM. Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance.Sports Med 2026.PubMed 41966639 · doi:10.1007/s40279-026-02437-0
  4. Renke G, Chinellato L. Therapeutic Peptides in Aesthetic, Metabolic and Endocrine Conditions: Effects, Safety, Clinical Applications, and Future Perspectives.Int J Mol Sci 2026.PubMed 42123471 · doi:10.3390/ijms27093890
  5. Coutinho LFD, DE Oliveira Neves LF, Camilo RP. A new era of doping? Use of peptide and peptide-analog drugs in recreational and professional sport and bodybuilding: a critical review.J Sports Med Phys Fitness 2026.PubMed 41880199 · doi:10.23736/S0022-4707.26.17773-1
  6. Gobburu JV, Agersø H, Jusko WJ, et al.. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers.Pharm Res 1999.PubMed 10496658 · doi:10.1023/a:1018955126402
  7. Beck DE, Sweeney WB, McCarter MD, et al.. Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients.Int J Colorectal Dis 2014.PubMed 25331030 · doi:10.1007/s00384-014-2030-8
  8. Villegas Meza AD, Nocek M, Mitchell BC, et al.. Injectable Peptides in Sports Medicine: A Structured Narrative Review of Evidence, Safety, and Antidoping Implications.JBJS Rev 2026.PubMed 42160466 · doi:10.2106/JBJS.RVW.26.00027
  9. Memdouh S, Gavrilović I, Ng K, et al.. Advances in the detection of growth hormone releasing hormone synthetic analogs.Drug Test Anal 2021.PubMed 34665524 · doi:10.1002/dta.3183
  10. Walker RF. Sermorelin: a better approach to management of adult-onset growth hormone insufficiency?.Clin Interv Aging 2006.PubMed 18046908 · doi:10.2147/ciia.2006.1.4.307
  11. Ramirez G, Herrera R, Pineda D, et al.. The effects of high altitude on hypothalamic-pituitary secretory dynamics in men.Clin Endocrinol (Oxf) 1995.PubMed 7641401 · doi:10.1111/j.1365-2265.1995.tb01887.x
  12. Popovic V, Pekic S, Golubicic I, et al.. The impact of cranial irradiation on GH responsiveness to GHRH plus GH-releasing peptide-6.J Clin Endocrinol Metab 2002.PubMed 11994347 · doi:10.1210/jcem.87.5.8485
  13. Saenger P, Pescovitz OH, Bercu BB, et al.. Outcome of growth hormone therapy in children with growth hormone deficiency showing an inadequate response to growth hormone-releasing hormone.Endocrine 2001.PubMed 11572326 · doi:10.1385/ENDO:15:1:051

Literature retrieved from PubMed on October 16, 2026, favouring human studies and reviews. Numbered markers in the text show which paper supports which statement; uncited entries are background reading.

Read this first This page compares published reference data. It is not medical advice and not a recommendation to use either compound. Several compounds documented on this site are not approved for human use.